This account, drawn from a book by Ben Macintyre, recounts how MI6 recruited a senior KGB officer as a double agent in Tehran in 1981, during the chaotic aftermath of Iran's Islamic Revolution. The officer, Vladimir Kuzichkin, revealed a Soviet plot in which underground Iranian communists would seize power and invite in the Red Army, a development the West feared could have handed Moscow control of the Persian Gulf's oil and ports and tipped the Cold War in the USSR's favour, potentially risking nuclear escalation.

Kuzichkin, a 6ft 4in KGB major, met his British contact, an MI6 officer, in a bugged embassy house, running taps and a radio to mask their conversation from Iran's secret police. In exchange for defecting and exposing the plot, Kuzichkin's price was help with severe impotence that was destroying his marriage, as he believed Western medicine could succeed where Russian treatment had failed. The MI6 officer agreed to help, and within the time it took to run a bath, Kuzichkin had become a Western asset, at immense risk to both men had they been discovered by Khomeini's Revolutionary Guards.